Due to the inherent, hydrophobic nature of many synthetic fibers, such as polyester, polypropylene, and others, fabrics formed entirely from these synthetic fibers exhibit poor moisture absorption and release properties. Many methods have been tried to enhance the hydrophilicity of polyester materials in order to achieve improved comfort in apparel fabrics. For example, hydrophilic co-monomers have been incorporated into polyethyleneterephthalate to give more hydrophilic fibers, but at the expense of fiber properties. Numerous hydrophilic polymeric finishes and chemicals have been applied to hydrophobic fabrics but have not met with widespread acceptance. They often affect the fabric hand, but a greater problem is their lack of permanence; the hydrophilic properties are frequently lessened or lost on laundering of the garments.
More permanent treatments, such as graft polymerization of hydrophilic vinyl monomers onto hydrophobic substrates, and the treatment of polyester materials with reducing agents such as lithium borohydride or various oxidizing agents, although fairly effective, add significant cost to the finished material. Both acid and base treatments of polyester materials have been described, but the improvement in hydrophilicity is offset by a significant loss in fabric strength due to hydrolysis of the ester linkages.
A technique that has been used successfully to improve the comfort of polyester in apparel fabrics is to blend polyester staple with 35 to 50% of a hydrophilic fiber, such as cotton or wool. Although woven or knit fabrics made from spun yarns of polyester with 35 to 50% cotton are very comfortable when dry, they become uncomfortable when wet due to the high moisture absorption of cotton. This is especially undesirable in cold weather when absorbed perspiration due to physical exertion can cause hypothermia while resting.
Therefore, there exists a need for a fabric that will provide increased comfort to the wearer. More specifically, there is a need for a fabric which is capable of quickly absorbing perspiration from the skin of the wearer, but which will also quickly release the moisture so that the moisture content in the fabric remains low.